Bovine serum albumin

About: Bovine serum albumin is a research topic. Over the lifetime, 19981 publications have been published within this topic receiving 571291 citations. The topic is also known as: BSA.

Determination of vitamin D status by radioimmunoassay with an 125I-labeled tracer.

Abstract: We report here the first radioimmunoassay for a vitamin D metabolite utilizing a radioiodinated tracer. Antibodies were generated in a goat immunized with the vitamin D analog 23, 24, 25, 26, 27-pentanor-C(22)-carboxylic acid of vitamin D, coupled directly with bovine serum albumin. The 125I-labeled tracer was prepared by reacting a 3-amino-propyl derivative of vitamin D-C(22)-amide with Bolton-Hunter reagent. The primary antiserum, used at a 15,000-fold final dilution, cross-reacted equally with all cholecalciferol and ergocalciferol metabolites tested except 1,25-dihydroxycalciferol metabolites and the parent calciferols; the antiserum did not cross-react with dihydrotachysterol. Calibrators were prepared in vitamin D-stripped human serum. 25-Hydroxycholecalciferol was quantitatively extracted from serum or plasma (50 microL) with acetonitrile. The assay consists of a 90-min incubation at room temperature with primary antiserum, followed by a 20-min incubation with a second antiserum and separation of bound from free fractions by centrifugation. The detection limit of the assay was 2.8 micrograms/L for 25-hydroxycholecalciferol. Results with the present assay compared well with those from a liquid-chromatographic procedure involving specific ultraviolet detection of 25-hydroxycalciferol in plasma.

In situ preparation of protein-"smart" polymer conjugates with retention of bioactivity.

Abstract: Protein−polymer conjugates are widely used in biotechnology and medicine, and new methods to prepare the bioconjugates would be advantageous for these applications In this report, we demonstrate that bioactive “smart” polymer conjugates can be synthesized by polymerizing from defined initiation sites on proteins, thus preparing the polymer conjugates in situ In particular, free cysteines, Cys-34 of bovine serum albumin (BSA) and Cys-131 of T4 lysozyme V131C, were modified with initiators for atom transfer radical polymerization (ATRP) either through a reversible disulfide linkage or irreversible bond by reaction with pyridyl disulfide- and maleimide-functionalized initiators, respectively Initiator conjugation was verified by electrospray-ionization mass spectroscopy (ESI-MS), and the location of the modification was confirmed by μLC-MSMS (tandem mass spectrometry) analysis of the trypsin-digested protein macroinitiators Polymerization of N-isopropylacrylamide (NIPAAm) from the protein macroinitiators

Radioimmunoassay for the vitamin K-dependent protein of bone and its discovery in plasma.

Abstract: The vitamin K-dependent protein of bone has been detected in human plasma by radioimmunoassay at 4.5 ng per ml. The plasma protein has the same apparent molecular weight as the pure bone Gla protein (BGP) and other studies indicate the plasma protein is probably the intact bone protein. BGP also has been detected in bovine serum by radioimmunoassay. The bovine serum levels of BGP decrease with developmental age from 200 ng per ml in fetal calves to 26 ng per ml in adult cows. The implications of the discovery of BGP in plasma to the function of this unique protein are discussed. This assay employs rabbit antibody directed against calf BGP and has a sensitivity of 0.1 ng. The antibody crossreacts with purified human BGP but not with BGP from rat or rabbit bone. Studies with peptides of known structure derived from enzymatic digests of BGP indicate that the rabbit antibody recognizes the COOH-terminal region of the 49-residue calf bone protein.